Study On Energy-consumption Performance Of Different Yield Points Reinforced Concrete Column

Traditional reinforced concrete column composed by the single kind of steel bars. Considering antiseismic requirements, designers general consider the design ideas of "strong column weak beam",using high strength steel bars and high strength concrete in reinforced concrete column. In elastic stage,the reinforced concrete column has high stiffness, low energy consumption,but the concrete is high brittleness. If the reinforced concrete column yield, it will loss load capacity.According to the above disadvantages in reinforced concreted column, a new column, which consists of large deformation concrete and low yield point steel bars. Under antiseismic requirements, the column’s working principle is the low yield point steel bars early entrying into plastic deformation because of low yield point,formating energy dissipation capacity. High yield point steel bar is still in elastic state. When earthquake small, the high yield point steel bar can provide restoring force.It makes column can consume seismic energy in elastic state.The structure compared with ordinary reinforced concrete columns has the following significant features:(1) New reinforced concrete columns use the concrete with high toughness,which has great strain and good ductility. Therefore, the new reinforced concrete column in a low yield point steel will not get a sharp cracking or crushing,which greatly extend the working section of the plastic column. Thus,the energy dissipation capacity of this new type of reinforced concrete columns compared with the traditional reinforced concrete columns are significantly improved.(2)The reinforcement yield strength of the low yield point steel in new reinforced concrete column is about245Mpa. Under load, low yield point steel can earlier get into yield stage before high strength steel yields. Through its own plastic deformation to dissipate seismic energy,the damping of new reinforced concrete columns compared with ordinary reinforced concrete columns increased by80%or more. At the same time, the whole structure still has a strong elastic deformation of recovery.(3)Using a low yield point steel is equivalent to build a damper in a column,which can reduce space and improve the seismic capacity of the structure. Main aspects of this study are:(1) Material design.It Includes the design and preparation of concrete with high toughness, the choice of the low yield point and mechanical properties of steel and so on.(2) Structural Design.It Includes the construction form of columns,the amount of different reinforcing steels and the amount of different types of concrete(3) Experimental studyThrough the column and cyclic loading tests,we can study the process of their force, modes of failure, mechanisms of failure, restoring capacity of deformation, ductility of displacement, hysteretic behavior, stiffness degradation, energy dissipation.(4) Numerical modelWith the help of finite element software named ANSYS, we have the non-linear numerical simulation and validation to the concrete column.